CanCOG®: Pilot Trial of Cognitive Rehabilitation for Cancer Survivors

Screening rate will be assessed as the proportion of potentially eligible cancer survivors who undergo eligibility screening.

The eligibility rate will be assessed as the proportion of screened individuals who meet the eligibility criteria. Reasons for ineligibility will be documented whenever available.

Consent rate will be assessed as the proportion of eligible individuals who provide informed consent. Reasons for refusal to participate will be documented whenever available.

Retention rate will be assessed as the proportion of participants who remain enrolled until study completion. Reasons for withdrawal will be documented whenever available.

Assessment completion rate will be assessed as the proportion of participants completing assessments at each assessment time point. Reasons for missed assessments will be documented whenever available.

Intervention adherence will be assessed as the proportion of intervention sessions attended by participants allocated to the intervention group. Reasons for missed sessions will be documented whenever available.

Intervention fidelity, the extent to which the intervention is delivered according to the intervention manual and session plans, will be assessed through facilitator-completed fidelity checklists.

Acceptability of the intervention will be assessed using participant retention (proportion of participants who remain enrolled until study completion) and intervention adherence (proportion of intervention sessions attended by participants allocated to the intervention group).

Acceptability will be assessed through semi-structured interviews conducted with 10-15 participants from the intervention group.

Interviews will explore participants' perceptions of the intervention content, format, duration, group delivery, perceived usefulness, and barriers or facilitators to participation.

Acceptability will also be assessed through the Acceptability of Cognitive Rehabilitation Interventions Survey-Cancer Survivors (ACRIS-CS). This 11-item instrument evaluates participants' perceptions of the intervention's acceptability, including its perceived usefulness, appropriateness, and overall satisfaction. Higher scores indicate greater acceptability of the cognitive rehabilitation intervention.

Perceived cognitive functioning will be assessed with the Functional Assessment of Cancer Therapy-Cognitive Function version 3 (FACT-Cog v3). It consists of a 37-item self-report questionnaire composed of four subscales: Perceived Cognitive Impairments (CogPCI), Perceived Cognitive Abilities (CogPCA), Comments from Others (CogOth), and Impact on Quality of Life (CogQoL). The higher the score, the better the perceived functioning.

Global cognition will be assessed using the Montreal Cognitive Assessment (MoCA). The instrument's scores range from 0 to 30, with lower scores indicating poorer cognitive performance.

The test includes immediate recall across five learning trials, delayed recall after 30 minutes, and a recognition trial, allowing the assessment of acquisition, retention, and recognition processes. Lower scores indicate poorer performance.

Attention and processing speed will be assessed with the Trail Making Test Part A (TMT-A) and D2 Test of Attention.

TMT- A: Performance is based on completion time and errors. Higher adjusted scores correspond to better performance.

D2 Test of Attention: The scoring of this test provides the following results: Total Characters Processed, Total Correct Responses, Total Efficiency and Concentration Index. Higher scores suggest better performance.

Executive functioning and cognitive flexibility will be assessed using the Trail Making Test Part B (TMT-B). Performance is based on completion time and errors. Higher adjusted scores correspond to better performance.

Working memory will be assessed using the Wechsler Adult Intelligence Scale's (WAIS) - Digit Span subtest. It consists of three components: Digit Span forward, Digit Span Backward, and Digit Span sequencing. Higher scores indicate better performance.

Verbal fluency will be assessed with the Verbal Fluency Test (VFT). For the VFT, participants are required to remember, in one minute, the maximum number of words possible started by a specific letter or belonging to a specific category. A higher number of words recalled indicates better cognitive performance.

Inhibitory control will be assessed with the Stroop Color and Word Test. It consists of three tasks: reading words, naming colors, and identifying the color in which each word is written, regardless of the word's meaning. The performance is scored as the number of correct responses completed within the specified time for each condition. Higher scores indicate better performance.

Anxiety symptoms will be assessed using the Generalized Anxiety Disorder Scale (GAD-7). It consists of seven items evaluating the presence of anxiety-related symptoms. Scores range from zero to 21, with higher scores indicating greater anxiety severity.

Depressive symptoms will be assessed using the Patient Health Questionnaire-9 (PHQ-9), a 9-item self-report measure of depression severity based on DSM criteria. Total scores range from 0 to 27, with higher scores indicate more severe depressive symptoms.

Health-related quality of life will be assessed using a validated cancer-specific quality of life questionnaire, the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire, version 3 (EORTC QLQ-C30, version 3). The EORTC QLQ-C30, is a 30-item instrument including global health status/quality of life, functional, and symptom scales. Scores range from 0 to 100, with higher scores indicating better functioning/global quality of life and worse symptom burden on the symptom scales.